python = set(['绮梦','冷依依','香凝','紫轩'])
c = set(['冷依依','凌宇','紫轩','圣博'])
print('选择python语言的学生有:',python)
print('选择c语言的学生有:',c)
print('交集运算:',python & c)
print('并集运算:',python | c)
print('差集运算:',python - c)           